CHAP, vn] BLAS1-FURNACE, ETC.,

209

!h

I '

ing the ovens, so that practically half the gas would In that
case be available for the production of power in. engines.
This idea has heen worked out by Mr. Koppers, and at the
Anna Colliery of the Eschweiler Mining Co., near Ais-Ia-
Chapelle, there aie reported to be six batteries of Koppers
regenerator ovens, idth a power station designed for the
production of 16^000 H.P. from the surplus gas.
It is on. record * that at the "Wat-h Main Colliery, Wath-
tipon-Dearnea Rotherliam, an installation of SO Hiiessener
patent "by-product coke ovens, erected by the Coal Distillation
Co. of Middlesbrough—^representing the Actien Geselschaft
fuer Kohlendestillation—has been put in. The plant is to
produce 800 tons of Mast-furnace coke per -week, and there
Is to be available sufficient surplus gas and surplus waste
heat to produce 300 H.P. of electricity from the &0 ovens,
in addition to meeting the requirements for power for coal
grinding, elevating, and by-product plants. There are other
instances of similar enterprise -whereby English firms, on
discarding the old ** "beehive 5* type of oven, have been able to
obtain la-rge quantities of surplus power. Of course there are
other by-products besides power produced from coke ovens,
such as sulphate of ammonia, coal-tar and ben2ole.
129. The Shelton Iron Works have some Koerting Engines
"working on coke*OvemgaS€S3 and it has been found f that when
some coals aj*e used a calorific value of over.600 B.Th.U.J
per en. ft. is obtained* although 400' is more common. In no
case, hcweYer3 is tie quality constant during the whole period
oi coking. It usually de-creases from about 450 to 350 during
the operation. The gas .-passes through scrubbers, where the
a,mmondum sulphate and other "by-products are collected and
most of the tar removed. The gas then is divided into two
almost equal parts, oae half going to heat the coke ovens, and
the rest to tie production of power.. As the gas contains much
hydrogen, naphthalene, and other MgHy. infiammaTble bodies,
it> is li&Me to pre-ignition$3 and the compression is iept down
to 100 Ib. per sq. inch,, instead of the 140 Ib. per sq. inch, which
• * Times KS.» April 17, 1907.
t '"'Engineering', February 15, 190T, "
j About $30